The invention relates to a combustor assembly for a gas turbine and, more particularly, to a DLN combustor assembly including an acoustics resonator.
Gas turbine systems typically include at least one gas turbine engine having a compressor, a combustor assembly, and a turbine. The combustor assembly may use dry, low NOx (DLN) combustion. In DLN combustion, fuel and air are pre-mixed prior to ignition, which lowers emissions. However, the lean pre-mixed combustion process is susceptible to flow disturbances and acoustic pressure waves. More particularly, flow disturbances and acoustic pressure waves could result in self-sustained pressure oscillations at various frequencies. These pressure oscillations may be referred to as combustion dynamics. Combustion dynamics can cause structural vibrations, wearing, and other performance degradations.
It is desirable to suppress combustion dynamics in a DLN combustor below specified levels to maintain low emissions. For axial mode frequencies, which are typically below 500 Hz, combustion dynamics can be effectively controlled using acoustic resonators provided at optimal locations.